(19)

(11)

EP 0 452 423 A1

(12)

(43) Date of publication: 23.10.1991 Bulletin 1991/43 (21) Application number: 90907789.0 (22) Date of filing: 03.01.1990

(51) International Patent Classification (IPC):  C01B 13/ 18( . ) C01G 1/ 00( . ) C01B 13/ 32( . ) C01G 3/ 00( . ) (86) International application number: PCT/US1990/000057 (87) International publication number: WO 1990/008731 (09.08.1990 Gazette 1990/19)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI LU NL SE (30) Priority: 10.01.1989 US 19890296267 (71) Applicant: AlliedSignal Inc. Morristown, New Jersey 07962-2245 (US)	(72) Inventor: BARDER, Timothy, Joseph Addison, IL 60101 (US) (74) Representative: Brock, Peter William, et al  Urquhart-Dykes & Lord 1 Richfield Place Richfield Avenue Reading RG1 8EQ Berkshire Reading RG1 8EQ Berkshire (GB)